1. Field of the Invention
The invention relates generally to seismic energy vibrators and, more particularly, but not by way of limitation, it relates to an improved porting system for use in particular forms of vibration apparatus.
2. Description of the Prior Art
Prior vibrators that employ either single or dual pistons utilize two passages for oil to either side of the pistons. Illustrative of the prior art are U.S. Pat. Nos. 3,073,659; 3,159,233; and 3,745,885. The earlier teachings relating to reciprocating reaction mass seismic vibrators utilizing hydraulic drive have adhered to the relatively conventional methods of porting wherein the complete flow circuit is formed within the piston rod, whether it be a single or double rod end type of rod.